CVE-2026-48746
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedvLLM is an inference and serving engine for large language models (LLMs). From 0.3.0 until 0.22.0, a vulnerability in ASGI web servers and starlette's trust on those web servers enables an authentication bypass of the OpenAI API AuthenticationMiddleware. It allows to use the API without providing the configured VLLM_API_KEY or --api-key. This vulnerability is fixed in 0.22.0.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidencevLLM versions 0.3.0 through 0.22.0 contain an authentication bypass in the OpenAI API AuthenticationMiddleware. The vulnerability stems from ASGI web servers and starlette improperly trusting certain server configurations, allowing attackers to access the API without providing the configured VLLM_API_KEY or --api-key credential.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data>= 0.3.0, < 0.22.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check installed vLLM versionRun 'pip show vllm' or 'vllm --version' to retrieve the installed version numberAffected if The version is >= 0.3.0 and < 0.22.0
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Verify API server is enabledCheck if the vLLM API server process is running or if --api-key flag / VLLM_API_KEY environment variable has been configuredAffected if The API server is running with any authentication configuration present (VLLM_API_KEY set or --api-key specified)
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Confirm ASGI server integration is in useIdentify if the starlette-based API server is being used (default behavior for vLLM serving), typically accessible on port 8000 or configured --portAffected if The default ASGI-based API server is active and exposed on a network interface
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Test authentication bypassAttempt an API request without providing the X-API-Key header to a protected endpoint (e.g., /v1/models) and observe if access is grantedAffected if Requests succeed without authentication despite VLLM_API_KEY being configured
You are affected if vLLM version is between 0.3.0 and 0.22.0, the API server is running, and unauthenticated requests succeed despite having VLLM_API_KEY configured.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped0.22.0
Upgrade vLLM to version 0.22.0 or later to apply the authentication bypass fix. Verify that API key authentication is now enforced by testing API access without credentials.
vLLM 0.22.0
- Check the current installed version of vLLM using `pip show vllm` or `vllm --version`
- Upgrade to vLLM version 0.22.0 or later by running `pip install vllm>=0.22.0`
- After upgrading, restart the vLLM service to ensure the patched version is running
- Verify the authentication bypass is fixed by attempting to access the API without credentials (should be rejected)
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation1.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-48746 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-48746 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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